[pianotech] Making a fully fitted pinblock without measurements

[Ed Foote]

 Will writes: 



 


For some time I have been searching for the Holy Grail of locating the plate and a new pinblock to the case, without using measurements. 


 I have a far simpler method, and it keeps the tolerance to about .020" max. I do use wedges to measure the side to side, but they are usually not needed.   I drill two holes in each end of the plate down into the pinblock. In the treble, the line between these holes is parallel to the side of the piano, in the bass, it is often parallel to the stretcher. These holes are the same diameter as a small bridge pin and spaced several inches apart. 
     When the plate is removed, I cut heavy cardboard to fit exactly the corner of the piano and stretcher and tape them firmly in place.  I then drop the plate back in, screw it down with a couple or three block screws, and using the same holes, drill the cardboard.  
     After removing the plate and fitting a new, over sized block to it, I redrill the holes into the new block.  Then,I undo the block from the plate, and  by placing the cardboard templates over pins installed in the guide holes, I can draw a pencil line around the template, giving the the stretcher dimension as well as the exact end lengths and angles on the ends of the new block.. I then cut the block, taking the pencil line off the ends, and by placing a long straightedge along the stretcher lines, I pencil that in and cut the same way. This block will then be within half a pencil line of exact, which is plenty close enough. 
   It is also worth mentioning that many plates are flexed down at the tail, (particularly Steinways), so prior to unscrewing them from the block, I take out the rim bolts and nose bolts,(making note whether the nose bolts are holding the plate up or down), and record how much rise the tail exhibits with a wedge. This wedge will go back under the tail when I begin to reattach the block to the case.  
   The plate often distorts the block, so I screw the  new one in with all the screws at the webbing, and then put the whole thing back in the piano with resin under the ends and resin and dowels into the stretcher.  (The height has been recorded with a micrometer).  I let that sit overnight, then remove the plate, drill the dowels into the ends, and glue them in.   That is about all I need for an exact fit. 
Regards, 


Ed Foote RPT
http://www.uk-piano.org/edfoote/index.html

 

 

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